The present invention relates generally to methods and instruments for performing spinal surgery. Specifically, the invention concerns laparoscopic techniques and instruments to perform spinal surgeries.
The use of surgical techniques to correct the causes of low back pain, such as spinal injuries and deformities, has steadily increased over the last several years. One common procedure for relieving pain from the above-described problems is a discectomy, or surgical removal of a portion or all of an intervertebral disc, followed by implantation of a device between the adjacent vertebrae, such as a vertebral implant or fusion device. Typically, implantation of such a device is intended to promote bony fusion between the adjacent vertebral bodies.
Various surgical methods have been devised for implantation of devices into a subject disc space. For example, PCT International Publication No. WO 97/30666 to Zdeblick et al. discloses laparoscopic surgical techniques and instruments for preparing a disc space for implantation of fusion devices or implants. The laparoscopic instrumentation provides a sealed working channel to the disc space through which the disc space is distracted, the vertebral endplates and surrounding discs are reamed, and the vertebral implant inserted, all through a laparoscopic port engaged to the end of the sleeve. In this technique, a single sleeve is alternately placed at bilateral locations on the disc space through a single incision in the skin for insertion of a pair of fusion devices or vertebral implants at each location. A switching sleeve extends through the outer sleeve of the laparoscope to protect the tissue at the surgical site as the outer sleeve of the laparoscope is moved between bilateral locations. In order to move the outer sleeve, the switching sleeve is inserted and then the distractor fingers of the outer sleeve are withdrawn from the disc space at the first bilateral location. The outer sleeve and the switching sleeve are then manipulated through the skin to the second bilateral location. The techniques and instruments of the ""666 publication suffer from the disadvantage of requiring multiple manipulations of vessels and tissue adjacent the vertebral bodies to perform the procedure. Multiple manipulation of the vessels and tissues may increase the overall time of the procedure and increase the risk of damage to the vessels.
While the above described technique represents a significant advance over prior surgical procedures for spinal surgery, a need for improvement remains. In particular, procedures and instruments are required that minimize trauma to tissue surrounding the surgical site while allowing surgical procedures to be performed, such as spinal disc space preparations, implant insertion, and the like. There is also a need for instruments and techniques that maintain a sealed working channel during surgical procedures performed at multiple locations. The present invention is directed to these needs, among others.
The present invention includes surgical instruments and techniques for performing procedures at adjacent disc space locations in a generally sealed environment through a cap member having an access port alignable with a corresponding one of the disc space locations.
In one aspect of the invention, a method for performing a surgical procedure in a disc space between adjacent vertebrae is provided. The method includes accessing the disc space through skin and tissue of the patient. An instrument assembly including a sleeve is provided that has a distal end and an opposite proximal end. The sleeve defines a working channel between the distal and proximal ends. The working channel has a first portion and an adjacent second portion, and the working channel is sealable by a cap member secured to the proximal end of the sleeve. Preferably, the cap member has a sealable access port alignable with the first portion of the working channel. In a preferred aspect, the sleeve is advanced into the patient until the proximal end of the sleeve is positioned adjacent the disc space. The cap member can then be positioned with the access port aligned with the first portion or the second portion of the working channel while the sealed working channel is maintained.
Preferably, the disc space is prepared through the access port and first portion of the working channel. An implant may then be inserted through the access port and first portion with the working channel remaining substantially sealed. In a most preferred aspect, the access port is moved into alignment with the second portion of the working channel and the disc space is prepared for implant insertion through the access port and the second portion with the working channel remaining substantially sealed.
According to another aspect of the invention, an apparatus for performing a surgical procedure in the disc space between adjacent vertebrae of a patient is provided. The apparatus includes a sleeve having a distal end, an opposite proximal end, and a sealable working channel extending therethrough. The working channel has a first portion and an adjacent second portion each configured to receive surgical instruments therethrough. A cap member is secured to the second end of the sleeve. The cap member has an access port that seals the working channel when closed. The access port is alignable with a corresponding one of the first or second portions. The cap member can be moved with respect to the sleeve to substantially align the access port with the other of the first and second portions while the working channel remains sealed.
According to another aspect of the invention, an apparatus for performing a surgical procedure in the disc space between adjacent vertebrae of a patient is provided. The apparatus has a sleeve with a distal end, an opposite proximal end, and a working channel extending therebetween. The sleeve has a non-circular perimeter and a flange ring having a circular perimeter is secured at the proximal end of the sleeve. A cap member is secured to the flange ring at the proximal end, and has an access port. The cap member is movable about the flange ring to align the access port with a portion of the working channel while the working channel remains sealed.
According to yet another aspect of the invention, an apparatus for use in preparing a disc space for insertion of a vertebral implant is provided. The apparatus includes a sleeve that defines a working channel extending between a distal end and a proximal end. The working channel has a first portion and an adjacent second portion. A pair of distractors are each disposed in a corresponding one of the first and second portions. The distractors are coupled to the sleeve. Each of the distractors has a distractor tip for distracting the disc space when inserted therein. A cap member secured to the proximal end of the sleeve has a sealable access port for sealing the working channel. An impactor cap positionable over the cap member receives a driving force to insert the distractors in the disc space with the working channel sealed.